what is chemical bonding and why does it happen?
As it turns out, atoms bond together for a very simple reason: atoms like to have full valence shells. Ionic Bonding Let’s look at an example. Chlorine (Cl) has 17 total electrons: 2 in its 1st shell, 8 in the 2nd, and 7 in the 3rd. We know that the capacity of the 3rd shell is 8, so chlorine will try to pick up another electron to fill its outermost shell. Where does it get this electron? For some atoms it is easier to lose electrons than to pick up new ones. Sodium (Na), for example, has 11 total electrons: 2 in the 1st shell, 8 in the 2nd and 1 in the 3rd. For sodium to have a full valence shell it can do one of 2 things: pick up 7 new electrons (which is a very difficult thing to do) or give up one. If sodium gave up the 1 electron in its 3rd shell, this shell would now be empty and the 2nd shell (which is filled with 8 electrons) would become its valence shell. Thus chlorine and sodium are a perfect match for each other. One needs an electron and the other wants to lose an electro
